How to Use a Data Logger to Actually Make Your Driver Go Faster. First Data Logging   Article from Petri Ranta

Here are the questions I asked him to get us started.... and right away he reveals some great little tips!

Q: Let’s say I have one practice day to get some time out of my driver, what data would you say is the number one priority?

A: This is a difficult question to answer, however, this is how I would approach it. Taking into account that you are familiar to the track and you’re setup is in the ballpark so to speak, I would work with trying to get as close to the theoretical best lap as possible. This is a lap that the data logger software puts together using all of the drivers best segmented times (splits), and creates it as a goal. I have had many schools of thought on this, and if your driver can get to within 2-3 tenths of the theoretical best lap then your 9 times out of 10 close to the leaders or the leader at that point. Now, the data I would use to work on a driver to achieve more speed is having them carry more speed through the corners. This can be determined by reading the latitudinal G’s (G-force). The more speed being carried into the corners will create higher G’s; as a coach, mechanic, or a parent, ways to accomplish this is by having your driver run deeper into the corner, later breaking points, making sure that the chassis is tuned for more grip. Every datalogger will read the G-forces; one quick way of comparing sessions is by overlapping the graphs or looking at the numerical values. Most data logger software will give you the choice of looking at graphs or looking at numerical values, it is usually an icon at the top of the page you’re working with.

Q: Are you able to look at the data logging software on your laptop, and say where a driver is losing time on the circuit? If so, what information are you looking at?

A: If you really know your data interpretation, one should be able to differentiate between driver, chassis, and engine (drive train). There are many variables to look at when trying to determine lost time. Some classes are easier than others. With ICC, I would first look at the acceleration graphs and determine how my driver is shifting. You can tell by certain spikes in the graph if there is excessive wheel spin or if he/she is taking too long between gears.

Secondly, I would look at braking points. With the software at hand, you can pinpoint almost to the foot as to the de-acceleration points on a track. These bits of information really help, especially when comparing one driver to another under a team tent atmosphere.

With ICA, my main focus would be with two variables; first would be making sure that my driver is keeping their speed (RPM’s) up in the corners. The data logging software will tell you where the optimum horsepower and torque ranges are and keeping the engine at those marks or as close to will give you best results. Your receiving virtually the same information to a degree as you would get from a dyno, so keeping in mind there is a power range that gives you ultimate engine performance, this is a very important tool to be used at the track. The second point with ICA’s would be making sure that there is clean and clear acceleration lines while on the power. Meaning no flat spots on the graph, you want steady consistent inclines. Using graphs created by your temperature sensors coupled with the RPM graphs, one can sometimes find problem areas with carburetors resulting in extra information on whether it’s pumping properly and/or too lean or rich. Steering position and throttle input sensors will also help determine areas of lost time on a circuit, but we can discuss those in upcoming articles.

Q: Do you find that making set up changes yields best results, or concentrating on what the driver is doing when it comes to using the data logger?

A: I would say you have to use a combination of the two. Set up changes will really work well for you if you have a driver that can run consistent lap times. So sometimes in order to accomplish that, first you must work with the driver on how he/she is driving the course. You need to set up a basis point, so a few sessions in a relatively similar setup to create a basis lap time to determine a starting point, and then start to implement changes. At that point, the data logger will give you the required information you can use to start finding areas of improvement.

Q: Do you have a set procedure of how to manage your practice days; i.e. is there a logical process you go through to find a reduction in lap times?

A: I have three different procedures depending on class, driver, and weather. There always has to be a plan and I have one for almost every type of situation one could possibly come across. When you’re in the position of providing a data logging service, like I am, you have to make sure that you’re prepared. The downfall of this is that I could write a book on this topic alone.

Q: Is it better to leave data analysis until after the test day is over, rather than trying to interpret data at the circuit with the data logger and make changes?

A: If you really know what you’re reading when looking at the graphs, than using the data logger throughout the day will yield the best results. Knowing what to look for is the key. Interpreting data is a lot like anything else, you need to test, practice, and constantly play with it to become familiar, quick and efficient at it. There are still times when I will go home or back to the hotel after practice or race day and analyze more in depth. Because then you usually have the time to look at values or ideas you didn’t necessarily have time to look at while at the track.

Data Acquisition works, I can’t count the number of times I have brought drivers lap times down by simply interpreting the data and then making the necessary changes. Drivers need to listen to mechanics and mechanics need to listen to drivers – it’s that simple! Teamwork and understanding the data logger's graphs will guarantee faster lap times.

Pitfalls to avoid - use test days to download the data if you have never used it before. Keep good records of the changes you made and follow the sessions in order – then go home and work with the graphs and software. Read the manual and basically try not to learn the system while at an event, it will only frustrate you as practice at race days are precious and it is not the time to start learning the software or logger.

More data logging articles or all about data acquisition for karts